1. Field of the Invention
This invention relates to liquefied gas lighters, and is directed more particularly to a device for limiting the flame height of a liquefied gas lighter.
2. Description of the Prior Art
Most known devices used for limiting the flame height of liquefied gas lighters include a permeable element offering a resistance to the flow of the gas, thus determining the rate at which gaseous fuel is fed to the flame and hence the height of the flame.
When the permeable body is noncompressible, for example in the case of a sintered metallic or ceramic material, its intrinsic flow resistance determines the maximum gas flow rate and hence the maximum flame height provided by the lighter. When used on its own, such a device furnishes a flame with a nonadjustable height. It may also be used in series with additional means for adjusting the gas flow rate in order to provide a lighter with both an adjustable flame and a maximum flame height limited to a preset value as determined by the noncompressible permeable body.
It has been suggested to construct gas lighters having a maximum flame height limited to a certain preset value by encasing a noncompressible permeable body within a sleeve of high thermal conductivity (over 40 kcal/m/h/.degree.C.), which sleeve is in contact only with materials having low thermal conductivity (0.3 to 5 kcal/m/h/.degree.C.), in order to insulate the permeable body from unwanted heat inputs emanating from the burner. Gas lighters of such construction have been found frequently to exhibit the disadvantage of an unsteady flame in which the flame height gradually and substantially increases during the course of a single "burn. "